PRINCIPAL INVESTIGATOR(S): Ashton M. Graybiel, Earl F. Miller, and Jerry L. 



Homick 



EXPERIMENT TITLE/NUMBER : Human Vestibular Function, M131 



PROGRAM/MISSION : Skylab 2, 3, 4 



CLASSIFICATION : Human 



DISCIPLINED ) : Neurosensory 



OBJECTIVES : The three parts of this experiment were designed to determine 

 susceptibility to motion sickness, thresholds for perception of angular 

 acceleration as revealed by the oculogyral illusion, and the perceived 

 direction of internal and external space. 



PROTOCOL : The test parameters on the rotating litter chair were: 



1) rpm or constant rpm at varied rates (10-30 rpm) 



2) Clockwise, counterclockwise 



3) Front, back, right and left head movements 



4) Selected mission days beginning day 5, 6 or 7 



5) Eyes closed 



For oculogyral illusion (rotating litter chair and visual tracking of a line 

 target within goggles) the parameters were: _ 



1) Steps of constant angular acceleration from 0.02 /S to 3.0 /S 



2) Steps of constant velocity 



The stationary litter chair and goggles were used for pitch and roll 

 parameters. Measurement of postural equilibrium was determined by standing on 

 rails of random width during pref light and postf light tests. 



EQUIPMENT : Rotating litter chair, drive motor for chair rotation, control 

 console, otolith test goggle, custom bite boards, reference sphere and 

 magnetic pointer with readout device, balance rails. 



RESULTS : During rotation on litter chair, moderate to severe malaise (nausea) 

 was observed pref light and postf light for specific parameter combinations. 

 Modest malaise (epigastric discomfort, pallor) was observed inflight on the 

 crewmen of Skylab 2, disappearing immediately after the test. Slight malaise 

 (headache, flushing, dizziness) was observed inflight SL-3 (on 2 of 3 crewmen) 

 disappearing immediately after test. No symptomology was observed on Skylab 

 4. No significant changes preflight, inflight, and postflight were found in 

 perception of oculogyral illusion. Crewmen experienced drowsiness inflight, 

 but not preflight or postflight. No significant changes were found preflight, 

 inflight, and postflight in perception of pitch and roll. When testing for 

 postural equilibrium with eyes open, there was moderate postflight decrement 

 in 3 crewmen. For eyes closed, all crewmen showed postflight decrement, most 

 marked R+1. Recovery was essentially complete by R+11. 



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